Arrangement for sorting paper pulp and similar suspended matters



\ V.'RANTAN!EMI v ARRANGEMENT FOR SORTING PAPER-PULP March 28, 1950' v.

AND SIMILAR SUSPENDED MATTERS Filed Feb. 2, 1945 Patented Mar. 28, 1 950 ARRANGEMENT FOR SORTING PAPER PULP AND SIMILAR SUSPENDED MATTERS Viiinii Vilho Rantaniemi, Tammerfors, Finland,

assignor to Tammerfors Linne-Och Jernmanufaktur Aktiebolag, Tammerfors, Finland, a corporation of Finland Application February 2, 1945, Serial No. 575,806

In Finland March 18, 1944 3 Claims. 1

The present invention relates to an arrangement for sorting paper-pulp and similar suspensions wherein the suspended matter passes through a verticall disposed sifting cylinder, or screen and from the opposite side of which, usually the outer side, the suspended matter, which has been freed from coarse particles, is removed. In prior known sorters the suspended matter remains for the most part on both sides of the sifting cylinder, as a rule slightly higher on the intake side than on the outlet side, and the pressure on the latter side therefore remains, while the sorter is in motion, constantl in a certain decided relation to the pressure on the intake side.

The present invention constitutes an improvement in sorters of the above mentioned type and embodies means for varying the state of the suspended matter On the outlet side of the sifting cylinder and thereby the existing pressure during motion wherebythe capacity of the sorter may be increased or diminished and the degree of fineness in the sorted pulp maybe varied and wherein both of these capabilities may be predetermined and controlled.

The invention is illustrated in the accompanying drawings in which Figure 1 is a side view thereof partly in vertical section and partly in elevation, and Figure 2 is a view on lines IIII of Figure 1.

In the drawings:

l is the sifting cylinder or screen which is supported by the springs 2 and suspended from the upper lid 3. The bottom end of the cylinder is rendered elastic and solution-tight, by means of the rubber band 4 carried by the lower end of the cylinder and attached to the bottom of the sorter 5. The vibrator '5, by which the sifting cylinder can, in the prescribed manner, be brought into a vibratory motion and'by which its effect can be considerably increased, is fastened to the top member 1 of the sifting cylinder l.

The suspended matter to be sorted enters through the intake 8 passes into the central chamber 9 (Fig. 1) thence through the openings ID to the inside of the sifting cylinder, that is, the primar chamber -II where it is brought into a rotary motion, sweeping along the straining surface of the sifting cylinder or screen as a consequence of the construction of the intake openings i0 which have guiding surfaces or vanes I9 directed obliquely towards the cylinder I. The effect of the rotary motion can be enhanced by means of the jet-pipes I 1 which can add diluting water to the suspended matter in chamber I I, the water passing through the channels 16 which are connected to the water intake [5 and the jet pipes or spray nozzles are curved for the most part in the direction of the guiding surface IS. The finer particles of the suspension in chamber H penetrate through the screen and enter the encircling chamber l2 while the coarser particles float upwardly in chamber II and pass out through the central outlet I4, the discharge therethrough being advantageously promoted by means of a jet of water directed obliquely towards the surface of the suspension and introduced through the jet-pipe i8, the outlets of which are directed towards the outlet M.

In prior known sorters or strainers the finely strained suspension discharge is from the chamber 12 at only one point, that is, through an outlet l3. The container in' the present invention has been partitioned by means of a cylindrical wall 26 to provide an outer discharge chamber I22 and. a secondary chamber 12. In the partition wall 20 there are a number of series of outlet valves disposed at different heights, and as illustrated at three difierent heights, with four valves 2! in each series. The valves are arranged so that they can be regulated in series, each series by independent operating means including a control wheel 22 placed at the side of the sorter and driving a gear wheel 23, meshing with teeth 24 on the upper surface of a ring 25 to which the valve plates 2| are connected. Each ring 25 is slidably supported by circumferentially spaced supporting members 26. By decreasing or increasing the size of the openings regulated by valves 2| in the partition wall 20, and through which openings the strained matter flows from the inner chamber [2 to the outer chamber I22, the consistency of the strained matter, the counter pressure in the first named chamber and thereby the effect of the strainer as well as the degree of fineness of the strained suspension can be varied within a very wide range.

The outlets through which the strained matter is withdrawn at different heights from chamber l2 could also be made as separate annular outlet channels, and valves 2| could be adapted to be made regulative according to height whereby the partition wall 20 could also be constructed of annular parts with intervening slits, serving as outlets, the open height of which is regulated by the help of similar members corresponding to valves 2| which can be raised or lowered independently.

In such cases where a dilution of the finely strained suspension in chamber 52 is not disadvantageous the consistency of the pulp in this chamber can be influenced by the introduction of regulated quantities of diluting water to the suspension, therefore the outlet 13 should be made regulatable and dimensioned so that it is capable of withdrawing the increased amount of liquid. This. regulation is obtained through the weir 2'! although any other suitable flow controlling means could be employed. If desired the passage of the pulp in the strainer can also be reversed in which case the interior chamber of the strainer I must be partitioned as described in connection with the chamber l2, and the outer chamber provided with overflows, instead of outlet 23, for the removal of the coarse particles. If it is not desired to remove the suspension passing out through the different outlets by means of a common outlet, the suspension can also be divided up so that each separate stream passing out from these outlet openings is led away separately or mixed in a suitable manner. By means of a similar division one can also obtain, for example, 3-4 different kinds of suspensions. Thus this strainer can be utilized for fractionating.

I claim:

1. A strainer for paper pulp including a main container, means within the container for recciving the material to be strained in suspension and for straining the pulp, means for separately discharging heavy particles from the straining means, a partition wall'spacedly and concentrically surrounding said straining means and defining a secondary container and an outlet chamber, said wall having a plurality of series of circumierentially spaced discharge outlets, said series being vertically spaced from each other for selectively discharging strained material simultaneously at difierent heights into the outlet chamber, independent means for selectively adjusting the size of the outlets in the different series, the outlet chamber having a discharge outlet below the level of the lowermost series of outlets in the said wall and adjustable flow control means for said outlet for discharging the suspension of strained materials from the strainer at a rate corresponding to that of the suspension entering at different levels into the outlet chamber.

2. A strainer as defined in,and by claim 1 wherein a vertically disposed cylindrical straining screen is provided in the strainer and constitutes the straining means and wherein means are connected to the screen for vibrating the same.

3. A pulp strainer as defined in and by claim 1 wherein a vertically spaced series of circumferentially spaced supporting means are secured to the partition wall on the outlet side of the outlets therein, and wherein a ring element carrying a plurality of plate members each coacting with an outlet in the wall in a series of outlets andbeing carried by each series of the supporting means and constituting a control means for the size of the outlets in each series of outlets, and wherein independently operated means are connected to each ring to selectively rotate the same in either direction to thereby control the size of the outlets in each series of outlets and to selectively discharge strained suspension at different heights from the secondary container into the outlet chamber.

viimo VILHO RANTANIEMI.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,670,473 Milne May 22, 1928 1,676,652 Keller July 10, 1928 2,301,201 Chaplin Nov. 10, 1942 FOREIGN PATENTS Number Country Date 34,339 Austria Sept. 10, 1908 100,151 Sweden Oct. 29, 1940 

